Why do we need standard unit measurement?

Hint: The calculation for adequate care should be the same for everyone. Thus, calculation uniformity should be present.

Complete step by step answer:
A standard (or etalon) is an entity, device or experiment in metrology (the science of measure) that has a given relationship to the unit of measurement of a physical object. Standards are the basic reference for a weight and distance method to which all other measurement systems are evaluated.

To make our judgement more reliable and precise, we need a common unit of measurement. The calculation for proper support should be the same in case of everyone. Thus, measurement uniformity should be present. We need a popular set of measuring units, which are called regular units, just for sake of uniformity.

Additional Information:
SI unit's biggest advantage is it has an only unit (type of metric) in each quantity. This suggests that switching from one unit to another (within the system) is never required when there are no conversion variables to be memorised by students. The one and therefore only SI unit for length is metre.

The below are the major features of the standard unit:
(i) It should be readily comprehensible.
(ii) It can be updated as physical conditions alter.
(iii) It does not shift with time or location.
(iv) It can be duplicated with ease.

Note:
A measurement unit is a certain particular quantity selected as the norm from which other units of the same kind are made. The word standard extends to the physical entity on which the measuring device is centred.